Crematorium oven

ABSTRACT

The invention relates to a crematorium oven  1  comprising at least one combustion chamber  2  with a ceiling, wall  2.1  and base  3  on which to place the object to be cremated, a heat supply system  4,  a combustion air supply  5  and a flue gas outlet  6.  Within the ceiling and/or the wall  2.1  and/or the base  3  of the combustion chamber  2  at least one combustion air supply channel  7  and at least one flue gas return channel  8  are provided whereby the flue gas return channel  8  in the ceiling, and/or the wall  2.1  and/or the base  3  has an inlet  8.1  and an outlet  8.2.  In the ceiling and/or wall  2.1  and/or in the base  3  of the combustion chamber  2  the at least one combustion air supply channel  7  opens into the at least one flue gas return channel  8,  so that with the supplied combustion air a suction effect of the combustion air supply into the combustion chamber  2  is brought about. In this way at least part of the flue gas produced during the combustion process is drawn into the inlet  8.1  of the flue gas return channel  8  and emitted through the outlet  8.2  of the flue gas return channel  8  into the combustion chamber  2  and is thereby supplied to the combustion process again.

TECHNICAL FIELD

The present invention relates to a crematorium oven.

PRIOR ART

Crematorium ovens are already known from the prior art. They essentialcomprise a combustion chamber with a ceiling, wall and base on which toplace the object to be cremated, a heat supply system for heating thecombustion chamber as well as a combustion air supply and a flue gasoutlet.

Crematorium ovens are also known which have a combustion chamber withtwo combustion chamber sections, whereby in the first combustion chambersection preliminary incineration of the object to be cremated takesplace, with subsequent incineration of the remains from the firstcombustion chamber section taking place in the second combustion chambersection. Here, the cremation remains from a first incineration phaseremaining in a first combustion chamber section are transferred to thesecond combustion chamber section manually or with a removal device,whereby the heat produced in the first combustion section to incineratea second object for cremation is used for the subsequent incineration ofthe cremated remains in the second combustion chamber section.

In addition, through DE 601 06 043 T2 a rotating combustion system, witha flue gas return is known, in which part of the flue gas is diverted atthe central flue gas outlet and returned to the combustion process viathe central combustion air supply.

The disadvantage of the solutions known from the prior art is thatcrematorium ovens have a low efficiency so that during combustion a highenergy supply through the heat supply system is necessary and the fuelconsumption is therefore high. Furthermore the duration of a cremationis very long as it is determined by the difficult and slowly burningparts of the object being cremated.

DESCRIPTION OF THE INVENTION

This is the starting point of the invention. The object of theinvention, as characterised in the claims, is to provide a crematoriumoven, which allows the energy-efficient and rapid incineration of anobject to be cremated.

According to the invention this object is achieved by way of thecrematorium oven according to claim 1. Further advantageous details,aspects and embodiments of the present invention are set out in thedependent claims, the description, the examples and the drawings.

The present invention provides a crematorium oven comprising at leastone combustion chamber with a ceiling, wall and a base on which to placethe object to be cremated, a heat supply system, a combustion air supplyand a flue gas outlet. Within the ceiling and/or the wall and/or thebase of the combustion chamber at least one combustion air supplychannel and at least one flue gas return channel are provided, wherebythe flue gas return channel in the ceiling, and/or the wall and/or thebase has an inlet and an outlet. In the ceiling and/or wall and/or inthe base of the combustion chamber the at least one combustion airsupply channel opens into the at least one flue gas return channel, sothat the supplied combustion air causes a suction effect of thecombustion air supply into the combustion chamber. In this way at leastpart of the flue gas produced during the combustion process is drawninto the inlet of the flue gas return channel and emitted through theoutlet of the flue gas return channel into the combustion chamber and isthereby supplied to the combustion process again.

On the one hand the return of flue gas in accordance with the inventionbrings about a return of the thermal energy contained in the flue gas,and on the other hand the subsequent incineration of not fully burnedand/or still burnable components in the flue gas. Mixing of the flue gasreturned in the flue gas return channel with the combustion air takesplace and thereby preheats the combustion air. Further preheating of thecombustion air is brought about in that the flue gas return channel andthe combustion air supply channel are arranged in the ceiling and/or thewall and/or the base of the combustion chamber. During operation of thecrematorium these parts are at very high temperatures so that thetemperature of the combustion gas is considerably increased. Atsufficiently high temperatures the gas mixture ignites on that a flameemerges at the outlet to the flue gas return channel.

As a result of the flue gas return in accordance with the invention theefficiency of the crematorium oven is increased considerably. The energyrequirement of a crematorium oven can be reduced by 80% and more.Whereas conventional crematorium ovens require around 30 m³ to 35 m³ ofnatural gas to incinerate an object for cremation, the crematorium ovenin accordance with the invention consumes 6 m³ to 7 m³, in extreme caseseven 3 m³ to 5 m³ natural gas.

The combustion air supply channels can be arranged in any number ofloops within the ceiling and/or the wall and/or the base of thecombustion chamber. The longer the path of the combustion air supplychannels and the longer the supply time of the combustion air isextended, the more thermal energy is taken up by the combustion airthrough the strongly heated parts of the combustion chamber. Throughpreheating of the combustion air the object for cremation is morecompletely incinerated.

Particularly preferably several flue gas return channels and/or severalcombustion air supply channels are provided, which are preferablylocally arranged evenly distributed along the object to be cremated. Inthis way targeted, locally-distributed flue gas return and animprovement in the burning of difficult to burn and/or slowly burningparts of the object to be cremated can take place.

In addition, particularly when using several flue return channels, dueto the gas flowing into the combustion chamber from different directionsturbulences occur in the combustion chamber which results in furtherimproved incineration.

In a preferred embodiment at least one combustion air supply channelopens into several flue gas return channels. Through the alreadydiscussed mixing of the flue gas being returned in the flue gas returnchannel with the combustion air, and the ignition of the gas mixturethat takes place at sufficiently high temperatures, a flame emerges atthe outlet of the flue gas return channel which in the case of asuitably selected arrangement of the outlets of the flue gas returnchannels can be directed directly at the object to be cremated, moreparticularly the difficult to burn or slowly burning parts of the objectto be cremated.

In a preferred embodiment all the combustion air supply channels areconnected to a central combustion air supply. Through this centralcombustion air supply, pressurised combustion air is supplied to thecombustion air supply channels by way of a fan, for example, whichbrings about a suction effect in the flue gas return channels connectedto the combustion air supply channels. As a result of the central supplyof the combustion air supply channels with combustion air, a simplerdesign of the crematorium oven is achieved.

In the ceiling and/or in the walls and/or in the base of the combustionchamber the flue gas return channels have an inlet and an outlet. Inaccordance with a preferred embodiment the inlet of a flue gas returnchannel arranged in the wall is arranged above the outlet. Thisarrangement ensures that gases produced during the incineration processof the object to be cremated are drawn in at the inlet of the flue gasreturn channel in the upper part of the combustion chamber or combustionchamber sections, and emitted, preferably already ignited, in the lowerarea of the object to be cremated which burns more slowly, so that ashigh a heat exposure as possible acts of the difficult to burn parts ofthe object to be cremated, which thereby results in cremation that isefficient and reduced in terms of time.

In a second preferred form of embodiment the combustion chamber has afirst and a second combustion chamber section, whereby the firstcombustion chamber section is designed for the preliminary burning ofthe object to be cremated and the second combustion chamber section forthe subsequent incineration of the cremated remains and/ormineralisation of the ashes from the first combustion chamber section.In this way a further increase in efficiency is achieved, as the heatproduced during a further incineration process in the first combustionchamber section can be used for afterburning in the second combustionchamber section.

In a further preferred embodiment the base brings about an at leastpartial separation of the combustion chamber into a first and a secondcombustion chamber section, whereby the combustion gases produced in thefirst combustion chamber section are drawn off via the second combustionchamber section and the central flue gas outlet connected thereto. Aflue gas return channel passes through the base in such a way that acontinuous connection between the first and second combustion chambersection is produced. As a result of having the flue gas return channelsin the base, flue gases from the second combustion chamber section arereturned to the first combustion chamber section and through mixing withcombustion air are supplied, preferably ignited, to the underside of theobject to be cremated so that incineration of the underside of thelatter takes place.

In a particularly preferred embodiment the base has several elevationswhich are designed so that the object to be cremated is a placed at adistance from the base. Preferably the elevations are each providedadjacent to the outlets of the flue gas return channels. In this way thegases which are mixed with the combustion air and preferably ignited canflow around the object to be cremated and/or the flames emerging fromthe outlets of the flue gas return channels can blaze around theunderside of the object to be cremated so that especially these slowlyburning areas undergo accelerated incineration through the increasedheat effect.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below by way of examplesof embodiment with reference to the drawings. However, it is expresslypointed out that the invention is not intended to be restricted to theshown example.

FIG. 1 shows as an example a schematic lateral cross-section of acrematorium oven in accordance with the invention;

FIG. 2 shows as an example a partial cross-section through the wall ofthe crematorium oven in FIG. 1 along line A-A.

FIG. 3 shows as an example a partial cross-section along the base of thecrematorium oven in FIG. 1.

WAYS OF IMPLEMENTING THE INVENTION

In FIG. 1 reference number 1 denotes a crematorium oven in accordancewith the invention. Dashed lines indicate that the relevant object isnot shown in the sectional plan, but is located in the walls or in thebase of the crematorium oven. In the known manner the crematorium oven 1has a combustion chamber 2, which is surrounded by a wall 2.1 on itsouter circumference. In the shown example of embodiment the wall 2.1 isdesigned in several layers, namely an outer layer formed by a housing2.2. and a second internally adjoining layer forming an insulation 2.3.Provided on the housing 2.2. of the crematorium oven 1 is a heat supplysystem 4 which supplies thermal energy to the combustion chamber 2. Theheat supply system 4 is, more particularly, a burner, for example a gasor oil burner.

In order to make an incineration process possible within the combustionchamber the crematorium oven 1 also has a combustion air supply 5 and aflue gas outlet 6. Via the combustion air supply 5 pressurised air issupplied to the combustion chamber 2 by means of a fan for example. Thecombustion air can be fresh air, fresh air enriched with oxygen or alsopure oxygen. The flue gases produced during combustion are removed fromthe combustion chamber 2 via the flue gas outlet 6 and a chimneypreferably comprising a flue gas treatment device. In addition, aceiling (not shown) and abase 3 on which the object to be cremated isplaced for burning are provided in the combustion chamber 2.

In accordance with the invention in the ceiling and/or in the wall 2.1and/or in the base 3 of the combustion chamber 2 at least one combustionair supply channel 7 and at least one flue gas return channel 8 isprovided, whereby these channels 7, 8 are connected to each other insuch a way that through the suction effect of the combustion air supplyinto the combustion chamber 2 at least part of the flue gas producedduring the incineration is returned to the combustion process via theflue gas return channel 8.

In the shown example of embodiment a branched network of combustion airsupply channels 7 is provided in the wall 2.1 of the combustion chamber2 and in the base 3. The combustion air supply channels 7 are allconnected to the central combustion air supply 5 so that via thiscombustion air supply 5 pressurised combustion air is distributed intothe combustion air supply channel 7 by way of a fan for example.

Also provided within the wall 2.1 of the combustion chamber 2 and in thebase 3 are flue gas return channels 8, each with an inlet 8.1 and anoutlet 8.2. The flue gas return channels 8 within the wall 2.1 of thecombustion chamber 2 run parallel to the vertical axis HA of thecrematorium oven 1 and can be formed in the insulation 2.3 and/or casing2.2 or be formed by tubular elements arranged within the combustionchamber 2. In the shown example of embodiment the flue gas returnchannels 8 run at an acute angle to the vertical axis HA and preferablypass completely through the base. The flue gas return channels 8 arepreferably locally distributed along the lateral axis QA of thecombustion chamber 2.

To produce a suction effect within the flue gas return channels 8 thecombustion air supply channel 7 or branches from this combustion airsupply channel 7 are each connected to the individual flue gas returnchannels 8 in such a way that through the suction effect the flue gasproduced by the incineration is drawn into the inlet 8.1 and emittedthough the outlet 8.2.

In a preferred example of embodiment one combustion air supply channel 7or a branch from this combustion air supply channel 7 opens into severalflue gas return channels 8. In this way mixing of the drawn flue gaswith freshly supplied combustion air occurs in the flue gas returnchannels 8 and after ignition of the gas mixtures afterburning takesplace.

Particularly preferably the base 3 is arranged within the combustionchamber 2 in such a way that the combustion chamber 2 is divided into afirst and a second combustion chamber 2 a, 2 b. In relation to thevertical axis HA of the crematorium oven 1 the first combustion chambersection 2 a is preferably arranged above the second combustion chambersection 2 b. Through the base 3 the combustion chamber 2 is onlypartially divided into combustion chamber sections 2 a, 2 b so that gasproduced in the first combustion chamber section 2 a escapes, asindicated by the arrow 10, via the second combustion chamber 2 b and theflue gas outlet 6 provided there.

The object to be cremated is introduced into the first combustionchamber section 2 a in such a way that after a heating up phase of thecrematorium oven 1 through the supply of energy from the heat supplysystem 4 it is placed at least partially on the base 3. Preferably theobject to be cremated does not lie completely on the base 3 but is heldon elevations 9 at a distance from the base 3. Subsequently, in a firstincineration phase the object to be cremated is burned in the firstcombustion chamber section 2 a. After the first incineration phase, theremaining, not completely incinerated remains of the object to becremated are transferred to the second combustion chamber section 2 bfor afterburning in a second incineration phase, so that after thesecond incineration phase complete cremation of the object to becremated has taken place.

FIG. 2 shows a flue gas return channel 8 incorporated into the wall 2.1of the combustion chamber 2 with a combustion air supply channel 7opening into it. The flue gas return channel 8 has an inlet 8.1 and anoutlet 8.2, whereby the inlet 8.1 is provided above the outlet 8.2. Inthe shown example of embodiment both the flue gas return channel 8 aswell as the combustion air supply channel 7 run within the insulation2.3.

The flue gas return channel 8 essentially comprises three channelsections 8.3, 8.4 and 8.5 running in an approximately straight line,whereby the first channel section 8.3 approximately runs perpendicularlyto the second channel section 8.4 and the second channel section 8.4runs approximately perpendicularly to the third channel section 8.5. Thefirst and third channel sections 8.3, 8.5 are in parallel and at adistance from one another and at the free end form the inlet 8.1 and theoutlet 8.2 respectively. The first to third channel sections 8.3, 8.4and 8.5 are connect to a continuous flue gas return channel 8 via archedchannel connection sections. In the arched channel connection sectionbetween the second 8.4 and the third channel section 8.5 the combustionair supply channels 7 or a branch from a combustion air supply channel 7opens into the flue gas return channel 8.

Through the supply of combustion air under pressure from the combustionair supply channel 7 in the direction of the outlet 8.2 a suction effectis produced in the first and second channel section 8.3 and 8.4 of theflue gas return channel 8. As a result of this, as shown by the arrow11, flue gas already produced by burning is drawn into the flue gasreturn channel 8. At the point where the flue gas return channel 8 joinsthe combustion air channel 7 the drawn-in gas is mixed with freshcombustion air so that at the temperature predominating in thecombustion chamber 2 the gas mixture is already ignited in the thirdchannel section 8.5 of the flue gas return channel 8 so that at theoutlet 8.2 a flame emerges. The outlets 8.2 are preferably arranged insuch a way in relation to the object to be cremated that the flamesemerging at the outlets 8.2 act directly on the object to be cremated.

FIG. 3 shows a sectional view of the base of the crematorium oven 1 inaccordance with the invention. In the lateral direction the base 3,which at least partially separates the first combustion chamber section2 a from the second combustion chamber section 2 b is traversed by atleast one flue gas return channel 8 which has an inlet 8.1 on itsunderside and an outlet 8.2 on its upper side. In the area of the outlet8.2 the base 3 has an elevation 9, which in the shown example ofembodiment is in the shape of a tongue. The tongue-shaped elevation 9 isdesigned in such a way that at the top the outlet 8.2 is covered by theelevation 9. This effectively prevents combustion residues fallingthrough from the first combustion chamber section 2 a into the secondcombustion chamber section 2 b.

Also provided in the base 3 is a combustion air supply channel 7 or abranch from a combustion air supply channel 7 which opens into the fluegas return channel 8. Through the supply of pressurised combustion airin the combustion air supply channel 7 a suction effect is produced atthe inlet 8.1 of the flue gas return channel 8 which causes flue gas tobe returned from the second combustion chamber section 2 b into thefirst combustion chamber section 2 a. In the combustion channel 8freshly supplied combustion air is mixed with the returned flue gas fromthe second combustion chamber section 2 b and at a sufficiently hightemperature is ignited within the combustion chamber 2 so that a flameis produced in the flue gas return channel 8 and, more particularly, atthe outlet 8.2. The flames emerging at the outlet 8.2 surround thebottom of object to be cremated resulting in better incineration thereofat the places where the body is resting on the base of the coffin. Thiseffect is assisted decisively by the object to be cremated beingpositioned at a distance from the base 3 through the elevations 9.

Having thus described the invention, it is now claimed:

LIST OF REFERENCE NUMBERS

1 Crematorium oven

2 Combustion chamber

2 a First combustion chamber section

2 b Second combustion chamber section

2.1 Wall

2.2 Casing

2.3 Insulation

3 Base

4 Heat supply system

5 Combustion air supply

6 Flue gas outlet

7 Combustion air supply channel

8 Flue gas return channel

8.1 Inlet

8.2 Outlet

8.3 First channel section

8.4 Second channel section

8.5 Third channel section

9 Elevation

VA Vertical axis

LA Lateral axis

1. Crematorium oven (1) comprising at least one combustion chamber (2)with a ceiling, wall (2.1) and base (3) on which to place the object tobe cremated, a heat supply system (4), a combustion air supply (5) and aflue gas outlet (6), whereby within the ceiling and/or the wall (2.1)and/or the base (3) of the combustion chamber (2) at least onecombustion air supply channel (7) and at least one flue gas returnchannel (8) are provided, whereby the flue gas return channel (8) in theceiling and/or the wall (2.1) and/or the base (3) has an inlet (8.1) andan outlet (8.2) whereby in the ceiling and/or wall (2.1) and/or in thebase (3) of the combustion chamber (2) the at least one combustion airsupply channel (7) opens into the at least one flue gas return channel(8), so that with the supplied combustion air a suction effect of thecombustion air supply into the combustion chamber (2) is brought about,whereby at least part of the flue gas produced during the combustionprocess is drawn into the inlet (8.1) of the flue gas return channel (8)and emitted through the outlet (8.2) of the flue gas return channel (8)into the combustion chamber (2) and is thereby supplied to thecombustion process again.
 2. Crematorium oven according to claim 1characterised in that at least one combustion air supply channel (7)opens into several flue gas return channels (8).
 3. Crematorium ovenaccording to claim 1 characterised in that the inlet (8.1) of the atleast one flue gas return channel (8) is arranged in the wall (2.1) ofthe combustion chamber above the outlet (8.2) of the at least one fluegas return channel (8)
 4. Crematorium oven according to claim 1characterised in that the combustion chamber (2) has a first and asecond combustion chamber section (2 a, 2 b) whereby the firstcombustion chamber section (2 a) is designed for the incineration of theobject to be cremated and the second combustion chamber section (2 b) isdesigned for the afterburning of the ashes and/or the cremated remainsfrom the first combustion chamber section (2 a).
 5. Crematorium ovenaccording to claim 4 characterised in that the base (3) brings about atleast partial separation of the first combustion chamber section (2 a)from the second combustion chamber section (2 b).
 6. Crematorium ovenaccording to claim 5 characterised in that by way of at least one fluegas return channel (8) in the base (3) a connection between the firstand the second combustion chamber section (2 a, 2 b) is produced. 7.Crematorium oven according to claim 6 characterised in that the base (3)has several elevations (9) for positioning the object to be cremated ata distance from the base (3).
 8. Crematorium oven according to any oneof claim 7 characterised in that the flue gas outlet (6) is connected tothe second combustion chamber section (2 b).
 9. Crematorium ovenaccording to claim 2 characterised in that the inlet (8.1) of the atleast one flue gas return channel (8) is arranged in the wall (2.1) ofthe combustion chamber above the outlet (8.2) of the at least one fluegas return channel (8).
 10. Crematorium oven according to claim 2characterised in that the combustion chamber (2) has a first and asecond combustion chamber section (2 a, 2 b) whereby the firstcombustion chamber section (2 a) is designed for the incineration of theobject to be cremated and the second combustion chamber section (2 b) isdesigned for the afterburning of the ashes and/or the cremated remainsfrom the first combustion chamber section (2 a).
 11. Crematorium ovenaccording to claim 3 characterised in that the combustion chamber (2)has a first and a second combustion chamber section (2 a, 2 b) wherebythe first combustion chamber section (2 a) is designed for theincineration of the object to be cremated and the second combustionchamber section (2 b) is designed for the afterburning of the ashesand/or the cremated remains from the first combustion chamber section (2a).
 12. Crematorium oven according to claim 2 characterised in that byway of at least one flue gas return channel (8) in the base (3) aconnection between the first and the second combustion chamber section(2 a, 2 b) is produced, wherein the combustion chamber (2) has a firstand a second combustion chamber section (2 a, 2 b) whereby the firstcombustion chamber section (2 a) is designed for the incineration of theobject to be cremated and the second combustion chamber section (2 b) isdesigned for the afterburning of the ashes and/or the cremated remainsfrom the first combustion chamber section (2 a).
 13. Crematorium ovenaccording to claim 3 characterised in that by way of at least one fluegas return channel (8) in the base (3) a connection between the firstand the second combustion chamber section (2 a, 2 b) is produced,wherein the combustion chamber (2) has a first and a second combustionchamber section (2 a, 2 b) whereby the first combustion chamber section(2 a) is designed for the incineration of the object to be cremated andthe second combustion chamber section (2 b) is designed for theafterburning of the ashes and/or the cremated remains from the firstcombustion chamber section (2 a).
 14. Crematorium oven according toclaim 4 characterised in that by way of at least one flue gas returnchannel (8) in the base (3) a connection between the first and thesecond combustion chamber section (2 a, 2 b) is produced. 15.Crematorium oven according to claim 4 characterised in that the flue gasoutlet (6) is connected to the second combustion chamber section (2 b).16. Crematorium oven according to claim 5 characterised in that the fluegas outlet (6) is connected to the second combustion chamber section (2b).
 17. Crematorium oven according to claim 6 characterised in that theflue gas outlet (6) is connected to the second combustion chambersection (2 b).